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Hyundai and ethanol

I live in Michigan and recently drove to Connecticut. Turns out CT only has 10% ethanol gas available. The result was a drop of 20-25% in gas mileage and a very badly running engine. I took my 2012 Hyundai Elantra into the dealer. They flushed the system at a cost of $135 and the car is back to normal.

My problem: I will be moving to CT in the next few months. My car still has 2 yrs on the lease. What do I do about the ehtanol problem?

Any gasoline powered car should be able to run on 10% ethanol. The stuff has been around for decades, and most stations have nothing but 10% ethanol fuel. Even my old '71 Chevy pickup, designed to run on leaded gasoline, used it with no complaint other than a drop in gas mileage compared to pure gas. Are you sure you didn’t fill up with E85? Those pumps generally are labeled as such and have a yellow pump handle. Your car can only use that stuff if it has a yellow gas cap and/or is badged “flex fuel vehicle”. Filling a non-flex fuel vehicle with E85 will cause the problems you describe, so you either ended up doing that or got a bad batch of gas.

For what it’s worth, if you want ethanol free fuel, you can find stations here:

Your car should run fine on 10% ethanol. You will notice a drop in fuel economy, my anecdotal experience tells me it should be around a 5% decrease. If in fact the car didn’t return to running normal after refilling with the fuel you normally use then there’s more to the story. Perhaps you bought fuel that was more than 10%, perhaps there was some other contaminant, perhaps there’s more to what the dealer did.

Do you have the invoice from the dealer listing their diagnosis and trouble codes for your check engine light?

Hi SherryWinn,
I don’t have a solution to your problem but, having come across it, wanted to share my experience with ethanol. I have a 2004 Hyundai Santa Fe, 3.5L, 4WD. Virtually every tank of gas in this vehicle; now with 82k miles; has contained 10% ethanol, since, like you said, that is all that is available in many locations. My vehicle has always run great; I still have the original spark plugs and have not had injectors cleaned (I do add a bottle of Amsoil PI to gas every 5k). I get 24 mpg (highway average). When my Hyundai was only a year or so old I experimented (after some research to be sure I would not harm the engine) with 85% ethanol. I filled with this blend on three different, but not subsequent, occasions. My car ran normally but I think the computer was confused because my check engine light came on. It went out again after burning several gallons of gasoline (with 10% ethanol). My fuel economy dropped about 10% based, I guess, on its lower BTU content/Gasoline Gallon Equivalent. The E85, at that time, was quite a bit less expensive than gasoline so it more than balanced out. The reason I have not done this since, besides the computer confusion; which I could have possibly reprogrammed; is because ethanol, at that level, is corrosive. Vehicles designed for E85 have the components that come in contact with fuel made of, or lined with, special corrosion-resistant materials. I would like to hear what Click and Clack have to say on this subject…or anyone else out there with knowledge or an experience with ethanol.

I think the ethanol dissolved some crud that was already in the system.
Let loose, that caused havoc.
I bet a $5 bottle of Techron would have done the same thing as the $135 cleaning.

gregor, when the government stops subsidizing ethanol, which is due soon, it won’t be the big bargain anymore.

Hey keith-
I haven’t used E85 since 2005, when I lived in ND. I live in ID now and have no idea what the price is here, compared to 87 octane gasoline, in 2012. You are right though, without the subsidy, ethanol would cost more. Even gas with 10% ethanol blend will probably go up somewhat.

I am inclined to agree with Circuitsmith.

“I bet a $5 bottle of Techron would have done the same thing as the $135 cleaning.”

Maybe the dealer did just that for $135.